William Perlman/The Star ledgerSecond-year free-agent linebacker Spencer Paysinger is making plays like this sack of Tim Tebow

Spencer Paysinger had zoned out. He knows he shouldn’t have, but when Tom Coughlin began announcing the Giants’ three captains for last Friday’s game against the Chicago Bears, he allowed himself to wonder: “What if he said Paysinger?”

It was a longshot, a second-year undrafted linebacker receiving such an honor for the third — and most important — preseason game. But at the team hotel last Thursday night, Coughlin announced that David Diehl (offense), Mathias Kiwanuka (defense) and Paysinger (special teams) were the team captains for the next night.

As he announced his name, the Giants coach smirked at Paysinger, who could barely conceal a smile. “Ohhs” and “Ahhs” resonated throughout the room. Victor Cruz, sitting behind Paysinger, gave him a point and wink. Veterans, in full support, told him that a player this young had never been named captain for a game during their time with the Giants. Some mockingly called him "Capt."

“Naturally when you hear something like that, especially being in my position, you kind of want to take a small exhale,” Paysinger said. “But at the end of the day, cuts do have to be made.”

That is this week’s reality for Paysinger and other players vying for a coveted roster spot as the Giants take the field tomorrow night against the Patriots in the preseason finale. It's the last opportunity for players on the bubble — between making the final 53-man roster (the Giants have 75 players right now) and returning their playbooks Friday night — to showcase their ability.

The Giants, based on simple math, will have to make difficult decisions at linebacker.

A year ago, the linebacker position was considered the defense’s glaring weakness, as Jon Goff and Clint Sintim were lost for the season. Paysinger was one of four rookie linebackers — a combination of sixth-round picks and undrafted players — that made the final roster without an offseason of minicamps and organized team activities due to the lockout.

The rookies arrived at training camp without any understanding of the defense. Meetings in training camp were filled with anxiety as they meticulously took notes and tried to make sense of schemes without much success. On the field, they would make mistakes without knowing how and why.

“It was tough last year,” said Mark Herzlich, who went undrafted and entered last season without expectations after overcoming cancer just the year before. “I didn’t realize how tough it was last year until I saw this year, but it was definitely difficult. I’m surprised all four of us made it, to be honest.”

By the end of the Super Bowl-winning season, through the growing pains, three of the four (Herzlich, Greg Jones and Jacquian Williams) had started at least two games on defense and were instrumental on special teams. Williams stripped 49ers punt returner Kyle Williams to set up the game-winning field goal in the NFC Championship Game.

“Last year, we had a lot on our minds with just trying to understand what was going on with the defense, but now all of us have a completely better understanding of it,” Jones said. “We’re able to really focus on our opponent a lot better. I think that’s been the difference. We always got a lot to learn, all of us as young guys, but it’s been different.”

What also could be different is all four making the final roster.

The linebacker room — plus undrafted rookie Jake Muasau — now includes veteran Chase Blackburn, who joined the Giants in Week 13 last season and is penciled in as the starting middle linebacker, and offseason acquisition Keith Rivers.

That’s in addition to veterans Kiwanuka, who this time last year was recovering from a career-threatening neck injury, and Michael Boley, the quarterback of the defense.

The Giants, who carried seven linebackers on their final roster at the start of the 2011 season, placed Clint Sintim on the waived/injured list earlier in training camp.

Boley, now nursing a hamstring injury, said it’s the deepest the position has been since he arrived in East Rutherford in 2009.

“You can never have too many good players,” Coughlin said. “That’s one that you would look forward to. If you have that much competition, that’s a good thing. That’s what all spots should be like. I wish I could say that for every spot out here. The more the competition, the better the players practice, focus, perform.”

Paysinger called the linebacker competition a “silent battle” between close friends that has created a sense of camaraderie, which makes the reality of the NFL harsh.

“If someone does go, it’s going to be really tough because we’re like brothers,” Herzlich said of the four second-year players. “We came up together. We all knew what it was like those first couple days, those first couple weeks. We really grew together, not only on defense, but on special teams, too.

“It’s going to be. ... I don’t really like to think about it so, hopefully, that doesn’t have to happen.”